The present invention relates to propane tank systems and, more particularly, to gas delivery systems including a valve gas delivery system such as natural gas and arrangement which, among other advantages, enables repair personnel such as a driver-serviceman to readily check for leakage of gas from such systems.
Propane gas leaks can obviously cause serious problems. For example, fires resulting from such leaks can cause both property damage and personal injury including, in extreme cases, death. Thus, a very real need exists for an approach in testing for such leaks that will effectively protect the homeowner-users of propane gas. Such protection would also be of substantial benefit to the companies that serve such homeowner-users particularly in the area of reducing the spiraling costs of lawsuits involving the leakage of gas into the home of a customer from the propane system. This leakage is often from appliances that have inadvertently been left on at the time of a gas outage in the propane tank. In any event, whatever the cause of such leakage, it is obviously very important to be able to readily determine when there is leakage from the system.
There are strict rules associated with the assembly and servicing of propane systems. The current rules are set out in NFPA Pamphlet 58. Considering the rules that bear on the issues involved with the present invention, NFPA Pamphlet 58, Section 3-2.10 states that xe2x80x9cAfter assembly, piping systems (including hose) shall be tested and proven free of leaks at not less than operating pressure.xe2x80x9d Section 4.2.1 states that xe2x80x9cBefore gas is introduced into a system after being shut off, the entire system shall be inspected to determine that there are no open fittings or ends and all manual valves at outlets on equipment are closed and all unused valves at outlets are closed and plugged or capped.xe2x80x9d Section 4.2.2 states xe2x80x9cImmediately after turning on the gas the piping system shall be tested to ascertain that no gas is escaping.xe2x80x9d In addition, section 4.3.4 describes the process for purging (emptying of air from) a system that has been opened and states xe2x80x9cAfter the piping has been placed in operation, all equipment shall be purged and then placed in operation as necessary.xe2x80x9d
Section 4.1.4 of this pamphlet describes the methods of pressure testing and states as follows: xe2x80x9c(a) Test pressure shall be measured with a manometer or with a pressure measuring device designed and calibrated to read, record, or indicate a pressure loss due to leakage during the pressure test period. The source of pressure shall be isolated before the pressure tests are made. (b) The test pressure to be used shall be no less than 1 xc2xd time the proposed maximum working pressure, but not less than 3 psig, irrespective of design pressure. Where the pressure exceeds 125 psig, the test pressure shall not exceed a value that produces a hoop stress in the piping greater than 50 percent of the specified minimum yield strength of the pipe. (c) Systems for undiluted liquefied petroleum gases shall withstand the pressure test in accordance with (b) above, or, for single-staged systems operating at a pressure of xc2xd psig or less, shall withstand a test pressure of 9.0xc2x1xc2xd inch water column for a period of not less than 10 minutes without showing any drop in pressure. If the source of pressure for this test is a liquefied petroleum gas container, the container service valve shall be checked for positive shutoff with leak detector solution prior to the test, or shall be disconnected from the system during the test. (d) Test duration shall be not less than xc2xd hour for each 500 cubic feet of pipe volume or fraction thereof. When testing a system having a volume less than 10 cubic feet or a system in a single-family dwelling, the test duration shall be permitted to be reduced to 10 minutes. For a piping system having a volume of more than 24,000 cubic feet, the duration of the test shall not be required to exceed 24 hours.xe2x80x9d Finally, Section 4.1.2 (exception) states that xe2x80x9cFuel gas shall be permitted to be used in piping systems operating at pressures of 0.5 psig.xe2x80x9d
At present, there is no way for a driver-salesman or a service person, hereinafter referred to for convenience as a repairman or repair personnel, to check for leakage as described above without interrupting the gas piping, a process that is very time consuming. Further, this process introduces unwanted air into the system and thus requires such air to be purged.
There are, of course, many systems which use permanent valves and gauges for determining and/or controlling the pressure in the system. Reference is made in this regard to U.S. Pat. No. 2,923,312 (Wagner), U.S. Pat. No. 4,332,273 (Boyce) and U.S. Pat. No. 4,338,793 (O""Hern, Jr.) relating to refrigeration systems and to U.S. Pat. No. 4,702,754 (Blocker) relating to natural gas or propane delivery systems and U.S. Pat. No. 4,183,078 (Sorrell) relating to a combination shut-off and test-injection valve. Briefly considering some of these patents, the Wagner patent discloses a valve tool for charging and discharging refrigeration systems including a tee-adapter for testing gas pressures. The Boyce patent disclosed a leak-proof connector including a valve of the Schrader (or Schroeder) type while the O""Hern, Jr. patent discloses an adapter for a refrigeration system which also uses a normally closed Schrader valve. The Blocker patent discloses a test adapter which permits pressure tests to be carried out on delivery systems for fuel gas, i.e., propane or natural gas.
Reference is also made to U.S. Pat. No. 5,070,962 (Peterson, Jr.) which discloses a split valve test plug for use in a high pressure pipe line to sense pressure or temperature using a test probe and gauge. The plug valve includes a valve housing which is threaded into a tapped threaded opening in the pipe line.
Although reference is made above and in the discussion below to propane systems, similar problems occur in other gas delivery systems such as natural gas systems and as discussed hereinafter, the invention is not limited to propane systems.
According to one embodiment of the present invention, an assembly kit and method are provided which permit service or repair personnel to check a propane system for leaks at the time of introduction of propane into the system and which eliminates the need for the purging described above after the test. The service person is also assisted in ascertaining whether the system is actually out of gas, requiring interruption of service, in spite of the reading(s) provided by the tank gauge(s) since such gauges may be inoperative or may be giving false readings.
In accordance with a first aspect of the invention, a method is provided for use by propane tank service personnel in detecting escaping gas in propane tank systems including a regulator and a tank service valve connected together by a standard connector, the method comprising the steps of: replacing the standard connector with a permanent valve and connector assembly including first and second end connections and a branch connection portion, a valve unit disposed in said branch connection portion and including a valve stem actuable to open said valve unit, the replacing step including connecting said first and second end connections to the tank service valve and the regulator, respectively; and using a separate pressure gauge assembly individually assigned to tank service personnel and adapted to be carried by said personnel for testing the pressure in the propane tank, said pressure gauge assembly including a pressure gauge; a valve assembly connector including means for actuating the valve unit when the valve assembly connector is connected to the valve assembly, said testing of pressure comprising connecting the valve assembly connector of the pressure gauge assembly to the branch connection portion of the valve assembly to actuate the valve unit and thus provide an immediate reading of the tank pressure by said gauge, using the reading of tank pressure in determining whether the tank is out of propane gas, and thereafter taking one or the other of the following two steps depending on the determining step: if the tank is determined to not be out of propane gas, introducing gas into the tank as needed; and if the tank is determined to be out of propane gas, turning the tank service valve off, pressurizing the tank, turning the service valve on, introducing gas into the system to pressurize the system, thereafter turning the tank service valve back off again so as to isolate the gas introduced into the tank, and reading the gauge pressure to determine whether gas is escaping from the propane tank system. It will be appreciated that because each tank service person carries his or her own gauge assembly, a separate gauge is not necessary for each propane tank system and one gauge assembly only is needed by each service person.
In a preferred, advantageous embodiment, the gauge includes an indicating needle and further comprises a pressure scale and an ambient temperature scale calibrated relative to said pressure scale so that the position of the needle that provides a reading of gauge pressure on the pressure scale also provides a reading of the corresponding minimum ambient temperature on the ambient temperature scale, and the determining step for determining whether the tank is out of propane gas includes determining the actual ambient temperature and comparing the actual ambient temperature with the reading of said corresponding minimum ambient temperature.
According to a second aspect of the invention, a kit is provided for use in a propane tank system for enabling detection of escaping gas by tank repair personnel, the tank system including a standard connector connecting a regulator to a tank service valve, and the kit comprising: a valve and connector assembly for connection between the regulator and the service valve in place of the standard connector, the valve and connector assembly comprising a connector including end connections for connection to the regulator and the service valve, respectively, a main connector portion between the said end connectors, and a branch connector portion connected at one end thereof to the main connection portion, a valve unit disposed in the branch connector portion and including a valve stem actuable to open a connection to the main connector portion; and a separate pressure gauge assembly adapted to be carried by tank repair personnel and including a pressure gauge, and a mounting means, connected to the pressure gauge, for providing connection of the pressure gauge to the branch connector portion of the valve assembly, and for, when connected to said branch connector portion, providing actuation of the valve stem so that, in use with the tank service valve open, the pressure gauge provides a reading of the tank pressure and, in use with the system pressurized and the tank service valve closed, the gauge provides an indication of the presence of a leak or open line in the propane tank system.
The gauge preferably includes an indicating needle and further comprises includes a pressure scale and an ambient temperature scale calibrated relative to said pressure scale so that the position of the needle that provides a reading of gauge pressure on the pressure scale also provides a reading of the corresponding minimum ambient temperature on the ambient temperature scale.
The valve unit advantageously comprises a Schrader valve (also referred to as a Schrader-Bridgeport valve). Further, the means disposed at the other end of the hose of the gauge assembly preferably includes a finger pressure operated screw-on connector. The latter feature enables the gauge assembly to be connected to the system without the use of wrenches or the like.
Preferably, the main connector portion includes at least one flexible portion. Advantageously, the at least one flexible portion comprises a pigtail section.
In one preferred embodiment, the branch connector portion is welded to the main portion. Advantageously, the main connector portion includes a pigtail section and the branch connector portion is welded to the pigtail section.
In another preferred embodiment, the connector includes a straight pipe connector and one of the end connectors comprises left-hand threading on the straight pipe connector for connection to the service valve.
In yet a further embodiment, the branch connector portion includes a quick coupling valve unit and the mounting means of said pressure gauge assembly includes a cooperating quick coupling connector.
In accordance with yet another aspect of the invention, a kit is provided for use in a propane tank system for enabling detection of escaping gas by tank repair personnel, the tank system including a standard connector connecting a regulator to a tank service valve, and the kit comprising: a valve and connector assembly for connection between the regulator and the service valve in place of the standard connector, the valve and connector assembly comprising a connector including end connections for connection to the regulator and the service valve, respectively, a main connector portion between the end connectors and including an outlet hole therein along its length, and a branch connector portion connected at one end thereof to the main connector portion and terminating in a free end, the branch connector portion comprising a saddle valve unit directly connected to the main connector portion over the outlet hole and including a valve stem actuable to open a connection from the connector to the free end of the branch connector portion, and a separate pressure gauge assembly adapted to be carried by tank repair personnel and including a pressure gauge, and mounting means, affixed to the pressure gauge, for providing connection of the pressure gauge to said free end of the branch connector portion of the valve assembly, and for, when connected to said free end of the branch connector portion, providing actuation of the valve stem so that, in use with the tank service valve open, the gauge provides a reading of the tank pressure and, in use with the system pressurized and the tank service valve closed, the gauge provides an indication of the presence of a leak or open line in the propane tank system.
Preferably, the saddle valve unit includes outwardly extending spaced legs which fit around the main connector portion and are welded or soldered to the main connector portion.
According to a still further aspect of the invention, a method is provided for use by propane tank service personnel in detecting escaping gas in a propane tank system including a regulator and a tank service valve connected together by a valve and connector assembly including first and second end connections connected to the tank service valve and the regulator, respectively, a branch connection portion, and a valve unit disposed in the branch connection portion and including a valve stem actuable to open the valve unit, the method comprising using a separate pressure gauge assembly individually assigned to tank service personnel and adapted to be carried by said personnel for testing the pressure in the propane tank, the pressure gauge assembly including a pressure gauge; a valve assembly connector including means for actuating the valve unit when the valve assembly connector is connected to the valve assembly, and the testing of pressure comprising connecting the valve assembly connector of the pressure gauge assembly to the branch connection portion of the valve and connector assembly to actuate the valve unit and thus provide an immediate reading of the tank pressure by said gauge, using the reading of tank pressure in determining whether the tank is out of propane gas, and thereafter taking one or the other of the following two steps depending on the determining step: if the tank is determined to not be out of propane gas, introducing gas into the tank as needed; and if the tank is determined to be out of propane gas, turning the tank service valve off, pressurizing the tank, turning the service valve on, introducing gas into the system to pressurize the system, thereafter turning the tank service valve back off again so as to isolate the gas introduced into the tank, and reading the gauge pressure to determine whether gas is escaping from the propane tank system.
Preferably, the valve and connector assembly includes a main connection portion between the first and second end connections, an outlet hole is drilled into the main connector portion at an intermediate location therealong, and the valve unit comprises a saddle valve affixed to the main connector portion over the outlet hole.
In accordance with yet another important aspect of the invention, a kit is provided for use in a propane tank system for enabling detection of escaping gas by tank repair personnel, the tank system including a standard connector connecting a regulator to a tank service valve, and the kit comprising: a valve and connector assembly for connection between the regulator and the service valve in place of the standard connector, said valve and connector assembly comprising a connector including end connections for connection to the regulator and the service valve, respectively, a main connector portion between said end connectors, a branch connector portion connected at one end thereof to said main connector portion and terminating in a free end, and a monolithic manifold block, connected in said main connector portion between two sections thereof, for connecting said main connector portion to said branch connector portion, the manifold block including a through bore in which is received facing end portions of the two sections of the main connector portion and a further bore extending orthogonally to, and connected to, the through bore, the further bore including a drilled hole portion of smaller diameter than the remainder of the further bore located adjacent to, and in communication with, the through bore, the further bore receiving therein, and being connected to, a valve unit including a valve stem actuable to open a connection from the connector to the free end of the branch connector portion, and a separate pressure gauge assembly adapted to be carried by tank repair personnel and including a pressure gauge, and mounting means, affixed to said pressure gauge, for providing connection of said pressure gauge to the free end of the branch connector portion of the valve and connector assembly, and for, when connected to said free end of said branch connector portion, providing actuation of said valve stem so that, in use with the tank service valve open, the gauge provides a reading of the tank pressure and, in use with the system pressurized and the tank service valve closed, the gauge provides an indication of the presence of a leak or open line in the propane tank system.
According to yet another aspect of the invention, a kit is provided for use in a propane tank system for enabling detection of escaping gas by tank repair personnel, the tank system including a standard connector connecting a regulator to a tank service valve, and the kit comprising: a valve and connector assembly for connection between the regulator and the tank service valve, said valve and connector assembly comprising first and second end connectors for providing communication with the regulator and the service valve, respectively, and a monolithic manifold block, said manifold block including a through bore and at least one further bore extending orthogonally to, and connected to, said through bore, one of said bores including a drilled hole portion of smaller diameter than the remainder of said one bore located adjacent to, and in communication with, the other bores, said one bore receiving therein, and being connected to, a valve unit including a valve stem actuable to open a connection to the bores of the manifold block, these other bores including a threaded end portion and the end connectors including threaded end portions adapted to be received in the threaded end portions of the other bores, the kit further comprising a separate pressure gauge assembly adapted to be carried by tank repair personnel and including a pressure gauge, and mounting means, affixed to said pressure gauge, for providing connection of the pressure gauge to the valve unit such that, when the gauge is connected to said valve unit, the valve stem is actuated so that, in use with the tank service valve open, the pressure gauge provides a reading of the tank pressure and, in use with system pressurized and the tank service valve closed, the gauge provides an indication of the presence of a leak or open line in the propane tank system.
Preferably, the assembly further comprises a flow control valve unit, adapted to be connected, in use of the kit, between the tank service valve and the manifold block, for, when actuated, isolating the tank service valve.
In accordance with a further aspect of the invention, a connector assembly is provided for direct or indirect connection to the tank service valve of a propane tank system, the connector unit comprising a unitary monolithic manifold connector block including a through bore having opposite threaded ends and at least one further bore, extending orthogonally to, and connected to, the through bore, the at least one further bore having a threaded end, and one of said bores including a drilled hole portion of smaller diameter than the remainder of the associated bore, the assembly further comprising a valve unit including a threaded end received in said one bore, and a first and second threaded connectors adapted to be received in two of said threaded ends.
In an advantageous embodiment, a flow control valve having a threaded end is connected to one of said threaded ends between said manifold block and an associated one of said connectors, the associated connector being adapted to be connected to the tank service valve and the flow control valve, when closed, shutting off the connection between the tank service valve and the manifold block.
The at least one further bore preferably comprises a further through bore extending orthogonally to the first mentioned through bore and having threaded opposite ends. Advantageously, a pressure bleed valve is connected to one of the threaded ends.
According to a further aspect of the invention, a pressure gauge test device is provided for testing mobile pressure gauges used by driver and service personnel for propane tank systems, the device comprising: a unitary monolithic connector block including first and second orthogonal through bores therein providing four connection ports, a male connector connected to one of said ports, a female connector connected to a separate one of said ports, a pressure gauge permanently connected to a further one of said ports, and a valve unit connected to another one of said ports and including a valve stem, actuated responsive to connection to the valve unit of a pressure gauge to be tested, for, when actuated, opening a connection to the bores in the manifold block.
In accordance with a further embodiment of the invention, a liquid propane system is provided including a propane tank, a tank service valve connected to the tank, a pressure regulator connected to the tank service valve, and a flow control valve device connected between the tank service valve and the pressure regulator, the flow control valve device including pressure tap means for enabling gauge measurement of tank pressure and including a flow restrictive orifice having a diameter of no greater than 0.054 inches.
In one implementation, the valve device includes shut-off valve unit and said pressure tap means comprising a pressure tap unit separate from said valve unit and connected thereto.
In an alternative implementation, the valve device comprises a shut-off valve unit including valve body and said pressure tap means comprises pressure tap port formed integrally with said valve body. Advantageously, the shut-off valve unit includes a valve operator having a open and closed positions and a locking element for selectively locking said valve operator in either of said positions. Preferably, the valve operator comprises a valve handle, the valve unit further includes a valve stem and the locking element comprises a locking screw connecting said valve handle to said valve stem, said locking screw including a locking recess of a non-standard shape adapted to engage a locking tool including a screwdriver portion of a shape matching that of said locking recess. In one embodiment, the flow restrictive orifice is formed in said pressure tap port. In another embodiment, the flow restrictive orifice is formed in a separate component connected to said pressure tap port.
In accordance with yet another embodiment, a liquid propane system including a propane tank, a tank service valve connected to the tank, a pressure regulator connected to the tank service valve and comprising a first regulator stage, a second regulator stage, and a connection between said first and second stages, and a flow control valve device connected in the connection between said first regulator stage and said second regulator stage, said flow control valve device including pressure tap means for enabling gauge measurement of pressure in the connection between said first and second regular stages and including a flow restrictive orifice having a diameter of no greater than 0.054 inches.
In one implementation, the valve device includes shut-off valve unit and said pressure tap means comprising a pressure tap unit separate from and connected to said valve unit.
In an alternative implementation, the valve device comprises a shut-off valve unit including valve body and the pressure tap means comprises pressure tap port formed integrally with said valve body. Preferably, the shut-off valve unit includes a valve operator having a open and closed positions and a locking element for selectively locking said valve operator in either of said positions. Advantageously, the valve operator comprises a valve handle, the valve unit further includes a valve stem and said locking element comprises a locking screw connecting said valve handle to said valve stem, said locking screw including a locking recess of a non-standard shape adapted to engage a locking tool including a screwdriver portion of a shape matching that of said locking recess. In one embodiment, the flow restrictive orifice is formed in said pressure tap port. In another embodiment, the flow restrictive orifice is formed in a separate component connected to said pressure tap port.
According to a further aspect of the invention, a gas delivery system is provided including a gas service line, a pressure regulator connected in the gas service line, and a flow control valve device permanently installed at a predetermined location in said gas service line, said flow control valve device comprising a valve body including an integral pressure tap for enabling a measurement of gas pressure at said predetermined location; a valve operator having an open position in which flow takes place through the valve device and a closed position in which flow through the valve device is blocked and locking means for selectively locking said valve operator in said open position and in said closed position.
Advantageously, the valve operator comprises a valve handle, said valve unit further includes a valve stem and said locking element comprises a locking screw connecting said valve handle to said valve stem, said locking screw including a locking recess of a non-standard shape adapted to engage a locking tool including a screwdriver portion of a shape matching that of said locking recess. In an important implementation, the pressure tap includes a flow restrictive orifice formed therein.
In one embodiment of this aspect of the invention, the system comprises a propane delivery system including a propane tank and a tank service valve, and said flow control valve device is connected between said tank service tank and said regulator. In a further embodiment, the system comprises a propane gas delivery system including a propane tank and a tank service valve, the regulator includes first and second regulator stages, and the flow control valve is connected between said first and second regulator stages.
In another embodiment the system comprises a natural gas delivery system and said valve is installed in said service line upstream of said regulator. Alternatively, or in addition, a valve is installed in said service line downstream of said regulator. In a further embodiment wherein said system comprises a natural gas delivery system including a gas meter, the valve is installed in said service line downstream of said meter.
According to a further aspect of the invention, a natural gas delivery system is provided including a gas service line, a pressure regulator connected in the gas service line, a gas meter connected in said gas service line, and a flow control valve device permanently installed in the gas service line downstream of said meter, said flow control valve device comprising a valve body including an integral pressure tap for enabling measurement of gas pressure at said meter, a valve operator having an open position in which natural gas flows through the valve device and a closed position wherein natural gas is blocked from flow through the valve device and locking means for selectively locking said valve operator in said open and closed positions.
Advantageously, the valve operator comprises a valve handle, the valve unit further includes a valve stem and the locking element comprises a locking screw connecting said valve handle to said valve stem, said locking screw including a locking recess of a non-standard shape adapted to engage a locking tool including a screwdriver portion of a shape matching that of said locking recess.
Other features and advantages of the invention will be set forth in, or apparent from, the following detailed description of the preferred embodiment of the invention.